Examine source code of Request Bridge

{
  "manifest_version": 2,
  "name": "Request Bridge",
  "version": "1.0",
  "description": "Fetches content from one URL and posts it to another",
  "permissions": [
    "storage",
    "activeTab",
    "notifications",
    "alarms",
    "https://query1.finance.yahoo.com/*",
    "http://localhost:3000/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Request Bridge"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "@fangs-request-brige-for-yahoo"
    }
  }
}